1. Field of the Invention
The present invention relates generally to fluid dispensing devices. More particularly, the invention concerns a novel dispenser for dispensing medicinal fluids, such as Bupivacane to ambulatory patients that uniquely comprises a flow rate control system that regulates the pressure of medicaments flowing to the patient.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
A number of different types of medicament dispensers for dispensing medicaments to ambulatory patients have been suggested in the past. Many of the devices seek either to improve or to replace the traditional gravity flow and hypodermic syringe methods which have been the standard for delivery of liquid medicaments for many years.
With regard to the prior art, one of the most versatile and unique fluid delivery apparatus developed in recent years is that developed by one of the present inventors and described in U.S. Pat. No. 5,205,820. The components of this novel fluid delivery apparatus generally include: a base assembly, an elastomeric membrane serving as a stored energy means, fluid flow channels for filling and delivery, flow control means, a cover, and an ullage which comprises a part of the base assembly.
Another prior art patent issued to one of the present applicants, namely U.S. Pat. No. 5,743,879, discloses an injectable medicament dispenser for use in controllably dispensing fluid medicaments such as insulin, anti-infectives, analgesics, oncolylotics, cardiac drugs, bio-pharmaceuticals, and the like from a pre-filled container at a uniform rate. The dispenser, which is quite dissimilar in construction and operation from that of the present invention, includes a stored energy source in the form of a compressively deformable, polymeric, elastomeric member that provides the force necessary to controllably discharge the medicament from a pre-filled container which is housed within the body of the device. After having been deformed, the polymeric, elastomeric member will return to its starting configuration in a highly predictable manner.
A more recent fluid dispensing apparatus invented by one of the named inventors of the present application is disclosed in U.S. Pat. No. 7,220,245. This apparatus comprises a compact fluid dispenser for use in controllably dispensing fluid medicaments, such as antibiotics, oncolylotics, hormones, steroids, blood clotting agents, analgesics, and like medicinal agents from prefilled containers at a uniform rate. The dispenser uniquely includes a stored energy source that is provided in the form of a substantially constant-force, compressible-expandable wave spring that provides the force necessary to continuously and uniformly expel fluid from the device reservoir. The device further includes a fluid flow control assembly that precisely controls the flow of medicament solution to the patient.